Flow cytometry is a technology in which multiple physical and optical characteristics of single small or microscopic particles, such as cells or microspheres, are analyzed as they flow in a fluid stream through one or more beams of light. Flow cytometry is an integral technology in nearly every bio-medical discipline including diverse biological assays in clinical settings. Additionally, flow cytometry is an important analytical platform to perform biological point detection, bio-surveillance, and forensic analysis in support of homeland defense.
In the flow cytometer, particles are carried to the light beam intercept in a fluid stream. When particles pass through the light beam, they scatter the light and any fluorescent molecules present on or in the particle fluoresce. These resulting optical signals are directed by means of optics to appropriate detectors which generate electronic signals proportional to the optical impulses striking them. These electronic signals are processed to gather data on each particle or event and subsequently analyzed to provide information about the sample. Various particle properties, such as particle size, granularity and fluorescence intensity, can be determined by a flow cytometer recording how the particle under interrogation scatters the incident light beam and emits fluorescence.
Flow cytometers typically incorporate expensive lasers with highly stable outputs in order to obtain the high detection sensitivity and resolution necessary in many applications. Unfortunately, the size and expense of typical flow cytometers currently restricts their use to clinical and laboratory environments. Such flow cytometers cost more than 30,000 US dollars to purchase. For many potential users of flow cytometers, instrumentation size and cost are important considerations that may limit the acceptance of these systems in broader applications.
There is a continuing need to provide improved systems and methods for measuring particles in a sample stream of a flow cytometer or other flow based analyzers which can be implemented at low cost and with reduced infrastructure requirements, such as electrical power or other laboratory-based requirements. Reducing size and cost nearly always speeds acceptance and adoption of new technology.